The Middle Atlantic Regional Center of Excellence (MARCE) proposes to harness and focus the extraordinary wealth of scientific ingenuity, innovation, and investigator experience that resides within the institutions in our region to support research on an array of NIAID Emerging and Category A-C pathogens. The over-arching theme for the MARCE Research Programs is Emerging pathogen-host interactions. Under this theme, we propose six Research Programs that are centered on the study of: specific emerging viruses (Programs I and II); targeted respiratory and enteric bacterial pathogens (Programs III and IV, respectively); Select or Emerging Agent toxins (Program V); and, development of novel diagnostic technologies to detect these chosen organisms or toxins (Program VI). Each Program contains five or six highly collaborative Research Projects from investigators at three or more institutions within the Middle Atlantic region. In all, ten different institutions in the MARCE are home to one or more of the Research Projects, and six additional institutions host collaborators on these MARCE projects, training activities, or core resources. That the Programs were intentionally founded on cross-institutional collaborations reflects the high degree of inclusiveness fostered by MARCE. As during our first funding period, we will pursue a balanced research agenda that includes a mix of very basic research, clear translational research involving potential products and clinical research that all aim, ultimately, to result in new or improved therapeutic, preventive or diagnostic products. Our Research Programs are supported by an array of training activities including a series of novel courses that were exceptionally well attended during our first funding period. A robust Career Development Program will bring a cadre of bright, motivated, young scientists into the broad area of biodefense and emerging infectious diseases research. Our Developmental Research Plan is designed to incorporate new projects, investigators, and institutions into the existing MARCE program and to emphasize innovative concepts, new technologies, and high-risk opportunities that demonstrate potential for high-yield novel results in the area of biodefense and emerging infectious diseases research. When coupled with our rigorous internal and external evaluation system that has resulted in continual replacement of projects to address our strategic mission over the past five years, the MARCE will represent an innovative, vibrant and flexible research program well suited to the translation of basic research on emerging pathogen-host interactions into therapeutic and vaccine targets and products.